• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.1-10
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• 2013

RFID(Radio Frequency Identification) system is non-contact identification technology. A basic RFID system consists of a reader, and a set of tags. RFID tags can be divided into active and passive tags. Active tags with power source allows their own operation execution and passive tags are small and low-cost. So passive tags are more suitable for distribution industry than active tags. A reader processes the information receiving from tags. RFID system achieves a fast identification of multiple tags using radio frequency. RFID systems has been applied into a variety of fields such as distribution, logistics, transportation, inventory management, access control, finance and etc. To encourage the introduction of RFID systems, several problems (price, size, power consumption, security) should be resolved. In this paper, we proposed an algorithm to significantly alleviate the collision problem caused by simultaneous responses of multiple tags. In the RFID systems, in anti-collision schemes, there are three methods: probabilistic, deterministic, and hybrid. In this paper, we introduce ALOHA-based protocol as a probabilistic method, and Tree-based protocol as a deterministic one. In Aloha-based protocols, time is divided into multiple slots. Tags randomly select their own IDs and transmit it. But Aloha-based protocol cannot guarantee that all tags are identified because they are probabilistic methods. In contrast, Tree-based protocols guarantee that a reader identifies all tags within the transmission range of the reader. In Tree-based protocols, a reader sends a query, and tags respond it with their own IDs. When a reader sends a query and two or more tags respond, a collision occurs. Then the reader makes and sends a new query. Frequent collisions make the identification performance degrade. Therefore, to identify tags quickly, it is necessary to reduce collisions efficiently. Each RFID tag has an ID of 96bit EPC(Electronic Product Code). The tags in a company or manufacturer have similar tag IDs with the same prefix. Unnecessary collisions occur while identifying multiple tags using Query Tree protocol. It results in growth of query-responses and idle time, which the identification time significantly increases. To solve this problem, Collision Tree protocol and M-ary Query Tree protocol have been proposed. However, in Collision Tree protocol and Query Tree protocol, only one bit is identified during one query-response. And, when similar tag IDs exist, M-ary Query Tree Protocol generates unnecessary query-responses. In this paper, we propose Adaptive M-ary Query Tree protocol that improves the identification performance using m-bit recognition, collision information of tag IDs, and prediction technique. We compare our proposed scheme with other Tree-based protocols under the same conditions. We show that our proposed scheme outperforms others in terms of identification time and identification efficiency.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.37-50
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• 2009

The purpose of this study was to investigate the effects of on-farm management systems(including the farm size, stocking density of growing-finishing phase, proportion of finisher diet and type of growing-finishing building) and pre-slaughter handling(including the transportation time and loading time) on carcass grade, the incidence of PSE pork, the meat quality score for intra-muscle fat, inter-muscle fat, subcutaneous fat and score for elasticity of market pigs. For this study, 248,787 pigs of 53 different farms were used to establish the pork quality assurance program and to meet the comsumer's need. The results are summarized as follows. 1. The farm size had significant influence on carcass grade, in which showing the higher grade by increasing the farm size. However, the incidence of PSE pork were not significantly differences among the farm size. The meat quality score for intra-muscle fat, inter-muscle fat, subcutaneous fat and score for elasticity of market pigs were not significant influenced by farm size. 2. The stocking density of growing-finishing phase was statistically significant for carcass grade, in which showing the higher grade in mid density group. However, the incidence of PSE pork was higher in high density group. The meat quality score for intra-muscle fat, inter-muscle fat and elasticity of market pigs were greater in mid density groups, but not influenced by stocking density for subcutaneous fat score. 3. The carcass grade and the incidence of PSE pork were not significantly influenced by transportation time. However, transportation time significantly affected the meat quality score, the meat quality score for intra-muscle fat, inter-muscle fat, subcutaneous fat and elasticity of the carcasses were superior in more than 1 hour transportation groups. 4. At any time loading, the carcass grade and PSE incidence were not significantly differences. However, the meat quality score for intra-muscle fat, inter-muscle fat and elasticity of market pigs were superior in before 10 AM groups, but not influenced by loading time for subcutaneous fat score. 5. The proportion of finisher diet had not significant influence on carcass grade, but PSE incidence affected by proportion of finisher diet, 21 percent or more group was higher PSE incidence. The meat quality score for intra-muscle fat and inter-muscle fat of the carcasses were superior in 21 percent or more fed finisher diet groups, but elasticity score of carcass had not influenced by the proportion of finisher diet. 6. The type of growing-finishing building was affected the carcass grade and PSE incidence of the market pigs, carcass grade and PSE incidence were superior in enclosed mechanical ventilation building groups. The meat quality score for intra-muscle fat and inter-muscle fat of the carcasses were not significantly differences by the type of finishing building, but the score of subcutaneous fat and elasticity of carcass were superior in opened natural ventilation building groups. In conclusion, the results of this study suggest that we have more precise on-farm management practice and the knowledge related to pre-slaughter handling skills to reduce the stress and improve the status of welfare of market pigs.

• 한국유가공학회:학술대회논문집
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• 2007.09a
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• pp.49-58
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• 2007

Inflammatory process leads to the well-known mucosal damage and therefore a further disturbance of the epithelial barrier function, resulting abnormal intestinal wall function, even further accelerating the inflammatory process[1]. Despite of the records, etiology and pathogenesis of IBD remain rather unclear. There are many studies over the past couple of years have led to great advanced in understanding the inflammatory bowel disease(IBD) and their underlying pathophysiologic mechanisms. From the current understanding, it is likely that chronic inflammation in IBD is due to aggressive cellular immune responses including increased serum concentrations of different cytokines. Therefore, targeted molecules can be specifically eliminated in their expression directly on the transcriptional level. Interesting therapeutic trials are expected against adhesion molecules and pro-inflammatory cytokines such as TNF-${\alpha}$. The future development of immune therapies in IBD therefore holds great promises for better treatment modalities of IBD but will also open important new insights into a further understanding of inflammation pathophysiology. Treatment of cytokine inhibitors such as Immunex(Enbrel) and J&J/Centocor(Remicade) which are mouse-derived monoclonal antibodies have been shown in several studies to modulate the symptoms of patients, however, theses TNF inhibitors also have an adverse effect immune-related problems and also are costly and must be administered by injection. Because of the eventual development of unwanted side effects, these two products are used in only a select patient population. The present study was performed to elucidate the ability of TNF-${\alpha}$ antibodies produced in sheep colostrums to neutralize TNF-${\alpha}$ action in a cell-based bioassay and in a small animal model of intestinal inflammation. In vitro study, inhibitory effect of anti-TNF-${\alpha}$ antibody from the sheep was determined by cell bioassay. The antibody from the sheep at 1 in 10,000 dilution was able to completely inhibit TNF-${\alpha}$ activity in the cell bioassay. The antibodies from the same sheep, but different milkings, exhibited some variability in inhibition of TNF-${\alpha}$ activity, but were all greater than the control sample. In vivo study, the degree of inflammation was severe to experiment, despite of the initial pilot trial, main trial 1 was unable to figure out of any effect of antibody to reduce the impact of PAF and LPS. Main rat trial 2 resulted no significant symptoms like characteristic acute diarrhea and weight loss of colitis. This study suggested that colostrums from sheep immunized against TNF-${\alpha}$ significantly inhibited TNF-${\alpha}$ bioactivity in the cell based assay. And the higher than anticipated variability in the two animal models precluded assessment of the ability of antibody to prevent TNF-${\alpha}$ induced intestinal damage in the intact animal. Further study will require to find out an alternative animal model, which is more acceptable to test anti-TNF-${\alpha}$ IgA therapy for reducing the impact of inflammation on gut dysfunction. And subsequent pre-clinical and clinical testing also need generation of more antibody as current supplies are low.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.469-497
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• 2015

In 2009 Iridium 33, a satellite owned by the American Iridium Communications Inc. and Kosmos-2251, a satellite owned by the Russian Space Forces, collided at a speed of 42,120 km/h and an altitude of 789 kilometers above the Taymyr Peninsula in Siberia. NASA estimated that the satellite collision had created approximately 1,000 pieces of debris larger than 10 centimeters, in addition to many smaller ones. By July 2011, the U.S. Space Surveillance Network(SSN) had catalogued over 2,000 large debris fragments. On January 11, 2007 China conducted a test on its anti-satellite missile. A Chinese weather satellite, the FY-1C polar orbit satellite, was destroyed by the missile that was launched using a multistage solid-fuel. The test was unprecedented for having created a record amount of debris. At least 2,317 pieces of trackable size (i.e. of golf ball size or larger) and an estimated 150,000 particles were generated as a result. As far as the Space Treaties such as 1967 Outer Space Treaty, 1968 Rescue Agreement, 1972 Liability Convention, 1975 Registration Convention and 1979 Moon Agreement are concerned, few provisions addressing the space environment and debris in space can be found. In the early years of space exploration dating back to the late 1950s, the focus of international law was on the establishment of a basic set of rules on the activities undertaken by various states in outer space.. Consequently environmental issues, including those of space debris, did not receive the priority they deserve when international space law was originally drafted. As shown in the case of the 1978 "Cosmos 954 Incident" between Canada and USSR, the two parties settled it by the memorandum between two nations not by the Space Treaties to which they are parties. In 1994 the 66th conference of International Law Association(ILA) adopted "International Instrument on the Protection of the Environment from Damage Caused by Space Debris". The Inter-Agency Space Debris Coordination Committee(IADC) issued some guidelines for the space debris which were the basis of "the UN Space Debris Mitigation Guidelines" which had been approved by the Committee on the Peaceful Uses of Outer Space(COPUOS) in its 527th meeting. On December 21 2007 this guideline was approved by UNGA Resolution 62/217. The EU has proposed an "International Code of Conduct for Outer Space Activities" as a transparency and confidence-building measure. It was only in 2010 that the Scientific and Technical Subcommittee began considering as an agenda item the long-term sustainability of outer space. A Working Group on the Long-term Sustainability of Outer Space Activities was established, the objectives of which include identifying areas of concern for the long-term sustainability of outer space activities, proposing measures that could enhance sustainability, and producing voluntary guidelines to reduce risks to long-term sustainability. By this effort "Guidelines on the Long-term Sustainability of Outer Space Activities" are being under consideration. In the case of "Declaration of Legal Principles Governing the Activities of States in the Exp1oration and Use of Outer Space" adopted by UNGA Resolution 1962(XVIII), December 13 1963, the 9 principles proclaimed in that Declaration, although all of them incorporated in the Space Treaties, could be regarded as customary international law binding all states considering the time and opinio juris by the responses of the world. Although the soft law such as resolutions, guidelines are not binding law, there are some provisions which have a fundamentally norm-creating character and customary international law. In November 12 1974 UN General Assembly recalled through a Resolution 3232(XXIX) "Review of the role of International Court of Justice" that the development of international law may be reflected, inter alia, by the declarations and resolutions of the General Assembly which may to that extend be taken into consideration by the judgements of the International Court of Justice. We are expecting COPUOS which gave birth 5 Space Treaties that it could give us binding space debris mitigation measures to be implemented based on space debris mitigation soft law in the near future.

• Tuberculosis and Respiratory Diseases
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• v.58 no.1
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• pp.31-42
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• 2005

Background : Peroxiredoxins (Prxs) are a relatively newly recognized, novel family of peroxidases that reduce $H_2O_2$ and alkylhydroperoxide into water and alcohol, respectively. There are 6 known isoforms of Prxs present in human cells. Normally, Prxs exist in a head-to-tail homodimeric state in a reduced form. However, in the presence of excess $H_2O_2$, it can be oxidized on its catalytically active cysteine site into inactive oxidized forms. This study surveyed the types of the Prx isoforms present in the pulmonary epithelial, macrophage, endothelial, and other cell lines and observed their response to oxidative stress. Methods : This study examined the effect of exogenous, excess $H_2O_2$ on the Prxs of established cell lines originating from the pulmonary epithelium, macrophages, and other cell lines, which are known to be exposed to high oxygen partial pressures or are believed to be subject to frequent oxidative stress, using non-reducing SDS polyacrylamide electrophoresis (PAGE) and 2 dimensional electrophoresis. Result : The addition of excess $H_2O_2$ to the culture media of the various cell-lines caused the immediate inactivation of Prxs, as evidenced by their inability to form dimers by a disulfide cross linkage. This was detected as a subsequent shift to its monomeric forms on the non-reducing SDS PAGE. These findings were further confirmed by 2 dimensional electrophoresis and immunoblot analysis by a shift toward a more acidic isoelectric point (pI). However, the subsequent reappearance of the dimeric Prxs with a comparable, corresponding decrease in the monomeric bands was noted on the non-reducing SDS PAGE as early as 30 minutes after the $H_2O_2$ treatment suggesting regeneration after oxidation. The regenerated dimers can again be converted to the inactivated form by a repeated $H_2O_2$ treatment, indicating that the protein is still catalytically active. The recovery of Prxs to the original dimeric state was not inhibited by a pre-treatment with cycloheximide, nor by a pretreatment with inhibitors of protein synthesis, which suggests that the reappearance of dimers occurs via a regeneration process rather than via the de novo synthesis of the active protein. Conclusion : The cells, in general, appeared to be equipped with an established system for regenerating inactivated Prxs, and this system may function as a molecular "on-off switch" in various oxidative signal transduction processes. The same mechanisms might applicable other proteins associated with signal transduction where the active catalytic site cysteines exist.

• Tuberculosis and Respiratory Diseases
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• v.59 no.4
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• pp.389-396
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• 2005

Background : Central venous catheters(CVCs) area major source of nosocomial infection. Chlorhexidine-silver sulfadiazine coated catheters (CHSS) were developed to reduce the rate of CVC infection. However, the clinical effectiveness of CHSS in comparison wth non-coated catheter (NCC) remains to be evaluated. Methods : From January 2004 to December 2004 in medical intensive care unit (ICU) of Asan Medical Center, CVCs were inserted in 446 cases. We retrospectively analyzed characteristics of patients and catheterization,the catheter-related infection rate and colonization, microbiologic findings, and insertion sites (subclavian, jugular, femoral) according to the type of inserted CVCs (NCC: 187 cases, CHSS: 259 cases). Catheter related infection is defined as catheter related bacteremia and catheter related non-bacteremic sepsis. Results : 1) The mean age of the patients in each group was $62{\pm}16$ years, $63{\pm}15$ years (p=0.42), and sex ratio 94:50, 141:69 (p=0.9) in NCC and CHSS. Duration of ICU admission ($29{\pm}37$, $26{\pm}44$ p=0.42), duration of mechanical ventilation ($17{\pm}22$, $15{\pm}19$ p=0.17), and APACHE III score at the time of CVC insertion ($81{\pm}34$, $82{\pm}37$ p=0.61) were not different between both groups. 2) Mean duration of catheterization was 118 in NCC and 119 in CHSS (p=0.98). Number of catheter-days was 2176 days in NCC and 3035 days in CHSS. Catheter-related infection occurred in 9 (4.8%) cases receiving NCC and 4 cases (1.5%) receiving CHSS. Catheterrelated infection incidence per 1000 catheter-days was 4.1 and 1.3, respectively (p=0.04). CHSS was associated with a significant reduction of infection in jugular catheters regarding to insertion sites (p=0.01). 3) Microorganisms causing infection were Staphylococcus aureus (n=3), Candida (n=3), coagulase-negative Staphylococci (n=2), and Klebsiella (n=1) in NCC, and Candida species (n=2), coagulase-negative Staphylococci (n=2), Proteus (n=1) in CHSS. Conclusion : CHSS has significantly reduced the episodes of infection compared to NCC in jugular catheterization in medical ICU.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.237-246
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• 2008

Purpose: Three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) were found to reduce the incidence of acute and late rectal toxicity compared with conventional radiation therapy (RT), although acute and late urinary toxicities were not reduced significantly. Acute urinary toxicity, even at a low-grade, not only has an impact on a patient's quality of life, but also can be used as a predictor for chronic urinary toxicity. With bladder filling, part of the bladder moves away from the radiation field, resulting in a small irradiated bladder volume; hence, urinary toxicity can be decreased. The purpose of this study is to evaluate the impact of bladder volume on acute urinary toxicity during RT in patients with prostate cancer. Materials and Methods: Forty two patients diagnosed with prostate cancer were treated by 3DCRT and of these, 21 patients made up a control group treated without any instruction to control the bladder volume. The remaining 21 patients in the experimental group were treated with a full bladder after drinking 450 mL of water an hour before treatment. We measured the bladder volume by CT and ultrasound at simulation to validate the accuracy of ultrasound. During the treatment period, we measured bladder volume weekly by ultrasound, for the experimental group, to evaluate the variation of the bladder volume. Results: A significant correlation between the bladder volume measured by CT and ultrasound was observed. The bladder volume in the experimental group varied with each patient despite drinking the same amount of water. Although weekly variations of the bladder volume were very high, larger initial CT volumes were associated with larger mean weekly bladder volumes. The mean bladder volume was $299{\pm}155\;mL$ in the experimental group, as opposed to $187{\pm}155\;mL$ in the control group. Patients in experimental group experienced less acute urinary toxicities than in control group, but the difference was not statistically significant. A trend of reduced toxicity was observed with the increase of CT bladder volume. In patients with bladder volumes greater than 150 mL at simulation, toxicity rates of all grades were significantly lower than in patients with bladder volume less than 150 mL. Also, patients with a mean bladder volume larger than 100 mL during treatment showed a slightly reduced Grade 1 urinary toxicity rate compared to patients with a mean bladder volume smaller than 100 mL. Conclusion: Despite the large variability in bladder volume during the treatment period, treating patients with a full bladder reduced acute urinary toxicities in patients with prostate cancer. We recommend that patients with prostate cancer undergo treatment with a full bladder.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.127-135
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• 2014

Purpose : By taking advantage of each imaging modality, the use of fused CT/MRI image has increased in prostate cancer radiation therapy. However, fusion uncertainty may cause partial target miss or normal organ overdose. In order to complement such limitation, our hospital acquired MRI image (Planning MRI) by setting up patients with the same fixing tool and posture as CT simulation. This study aims to evaluate the usefulness of the Planning MRI through comparing and analyzing the diagnostic MRI image and Planning MRI image. Materials and Methods : This study targeted 10 patients who had been diagnosed with prostate cancer and prescribed nonhormone and definitive RT 70 Gy/28 fx from August 2011 to July 2013. Each patient had both CT and MRI simulations. The MRI images were acquired within one half hour after the CT simulation. The acquired CT/MRI images were fused primarily based on bony structure matching. This study measured the volume of prostate in the images of Planning MRI and diagnostic MRI. The diameters at the craniocaudal, anteroposterior and left-to-right directions from the center of prostate were measured in order to compare changes in the shape of prostate. Results : As a result of comparing the volume of prostate in the images of Planning MRI and diagnostic MRI, they were found to be $25.01cm^3$(range $15.84-34.75cm^3$) and $25.05cm^3$(range $15.28-35.88cm^3$) on average respectively. The diagnostic MRI had an increase of 0.12 % as compared with the Planning MRI. On the planning MRI, there was an increase in the volume by $7.46cm^3$(29 %) at the transition zone directions, and there was a decrease in the volume by $8.52cm^3$(34 %) in the peripheral zone direction. As a result of measuring the diameters at the craniocaudal, anteroposterior and left-to-right directions in the prostate, the Planning MRI was found to have on average 3.82cm, 2.38cm and 4.59cm respectively and the diagnostic MRI was found to have on average 3.37cm, 2.76cm and 4.51cm respectively. All three prostate diameters changed and the change was significant in the Planning MRI. On average, the anteroposterior prostate diameter decrease by 0.38cm(13 %). The mean right-to-left and craniocaudal diameter increased by 0.08cm(1.6 %) and 0.45cm(13 %), respectively. Conclusion : Based on the results of this study, it was found that the total volumes of prostate in the Planning MRI and the diagnostic MRI were not significantly different. However, there was a change in the shape and partial volume of prostate due to the insertion of prostate balloon tube to the rectum. Thus, if the Planning MRI images were used when conducting the fusion of CT/MRI images, it would be possible to include the target in the CTV without a loss as much as the increased volume in the transition zone. Also, it would be possible to reduce the radiation dose delivered to the rectum through separating more clearly the reduction of peripheral zone volume. Therefore, the author of this study believes that acquisition of Planning MRI image should be made to ensure target delineation and localization accuracy.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.43-50
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• 2014

In case of all patients who receive radiation therapy, a treatment plan is established and all steps of treatment are planned in the same geometrical condition. In case of head and neck cancer patients who undergo simulated treatment through computed tomography (CT), patients are fixed onto a table for planning, but laid on the top of the treatment table in the radiation therapy room. This study excogitated and fabricated an adjustable holder for head and neck cancer patients to fix patient's position and geometrical discrepancies when performing radiation therapy on head and neck cancer patients, and compared the error before and after adjusting the position of patients due to difference in weight to evaluate the correlation between patients' weight and range of error. Computed tomography system(High Advantage, GE, USA) is used for phantom to maintain the supine position to acquire the images of the therapy site for IMRT. IMRT 4MV X-rays was used by applying the LINAC(21EX, Varian, U.S.A). Treatment planning system (Pinnacle, ver. 9.1h, Philips, Madison, USA) was used. The setup accuracy was compared with each measurement was repeated five times for each weight (0, 15, and 30Kg) and CBCT was performed 30 times to find the mean and standard deviation of errors before and after the adjustment of each weight. SPSS ver.19.0(SPSS Inc., Chicago, IL,USA) statistics program was used to perform the Wilcoxon Rank test for significance evaluation and the Spearman analysis was used as the tool to analyze the significance evaluation of the correlation of weight. As a result of measuring the error values from CBCT before and after adjusting the position due to the weight difference, X,Y,Z axis was $0.4{\pm}0.8mm$, $0.8{\pm}0.4mm$, 0 for 0Kg before the adjustment. In 15Kg CBCT before and after adjusting the position due to the weight difference, X,Y,Z axis was $0.2{\pm}0.8mm$, $1.2{\pm}0.4mm$, $2.0{\pm}0.4mm$. After adjusting position was X,Y,Z axis was $0.2{\pm}0.4mm$, $0.4{\pm}0.5mm$, $0.4{\pm}0.5mm$. In 30Kg CBCT before and after adjusting the position due to the weight difference, X,Y,Z axis was $0.8{\pm}0.4mm$, $2.4{\pm}0.5mm$, $4.4{\pm}0.8mm$. After adjusting position was X,Y,Z axis was $0.6{\pm}0.5mm$, $1.0{\pm}0mm$, $0.6{\pm}0.5mm$. When the holder for the head and neck cancer was used to adjust the ab.0ove error value, the error values from CBCT were $0.2{\pm}0.8mm$ for the X axis, $0.40{\pm}0.54mm$ for Y axis, and 0 for Z axis. As a result of statistically analyzing each value before and after the adjustment the value was significant with p<0.034 at the Z axis with 15Kg of weight and with p<0.038 and p<0.041 at the Y and Z axes respectively with 30Kg of weight. There was a significant difference with p<0.008 when the analysis was performed through Kruscal-Wallis in terms of the difference in the adjusted values of the three weight groups. As it could reduce the errors, patients' reproduction could be improved for more precise and accurate radiation therapy. Development of an adjustable device for head and neck cancer patients is significant because it improves the reproduction of existing equipment by reducing the errors in patients' position.

• Journal of Gastric Cancer
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• v.5 no.1
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• pp.10-15
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• 2005

Purpose: Recently the role of vitamins, folate in particular, has been emphasized in the maintenance of health. Folate deficiency is known to give rise to developmental delay, immature vascular disease, neural tube defect, acute leukemia, atherosclerotic vascular disease, delivery defects, breast cancer, and particularly gastrointestinal neoplasia. Methylenetetrahydrofolate reductase (MTHFR) is an essential enzyme in folate metaboism, and influences DNA synthesis and DNA methylation. Generally, folate deficiency is associated with gastrointestinal neoplasms. The amino-acid- changing and enzyme-activity-reducing nucleotide polymorphism (766C$\rightarrow$T/ Ala222Val) has been described in the MTHFR polymorphism and leads to low enzyme activity that may reduce the capacity of DNA methylation and possibly uracil mis-incorporation into DNA. These processes may be critical in the oncogenic transformation of human cells, especially in colorectal carcinomas. We investigated the relationship between the MTHFR polymorphism in gastric cancer and the tumor site, the smoking history, and the alcoholic history. Materials and Methods: Ninety-six (96) individuals with gastric cancer and 287 healthy persons were analyzed. Blood sampling was performed, PCR-RFLP was analyzed, and MTHFR polymorphism genotypes of C/C, C/T, and T/T were obtained and analyzed statistically for their correlation. Results: In the gastric cancer group there were 69 ($72\%$) males and 27 ($28\%$) females. There were also 58 cases ($60\%$) involving the gastric lower body, 20 cases ($21\%$) the gastric mid-body, and 18 cases ($19\%$) the gastric upper body. In the control group there were 169 ($59\%$) males and 118 ($41\%$) females. Among the gastric cancer, 56 ($61\%$) smoking patients, 40 ($39\%$) non-smoking patients, 45($47\%$) alcoholic patients, 51 ($53\%$) non-alcoholic patients. In the gastric cancer group, MTHER polymorphisms were C/C in 18 ($19\%$) cases, C/T in 59 ($61\%$) cases, T/T in 19 ($20\%$) cases. In the control group polymorphisms were C/C 116 ($40\%$) cases, C/T 103 ($36\%$) cases, and T/T 68 ($24\%$) cases (P=0.045). In cases of lower gastric body cancer, polymorphisms were C/C in 16 ($24\%$) C/C in 16 ($24\%$) cases and C/T or T/T in 42 ($72\%$) cases. In cases of upper and mid-body cancer, polymorphisms were C/C in 2 ($5\%$) cases and C/T or T/T 36 ($95\%$) cases (P=0.006). In the non-smoking patient group, polymorphisms were C/C in 5 (12%) cases and C/T or T/T in 35 ($88\%$) cases. In the smoking patient group, C/C in 13 ($23\%$) cases and C/T or T/T in 43 ($77\%$) cases (P=0.189). In the non-alcoholic patient group, polymorphisms were C/C in 6 ($12\%$) cases and C/T or T/T in 45 ($88\%$) cases. In the alcoholic patient group, polymorphisms were C/C in 12 ($26\%$) cases and C/T or T/T in 33 ($74\%$) cases (P=0.063) Conclusion: MTHFR polymorphisms are associated with gastric cancer and tumor site, but not with smoking and alcohol drinking.